Update README.md

README.md

@@ -44,6 +44,7 @@ I want to have a starter template for building Dotnet Apis. Things that are impo
 ## Architectural Decision Records
 - Have a thin endpoint/controller and move the logic into a handler/service class so it's (1) unit testable and (2) decoupled from the endpoint framework to ease with refactoring e.g. moving the handler to a `Core` or `Application` project.
 - (Exploring) Use [Result](https://www.milanjovanovic.tech/blog/functional-error-handling-in-dotnet-with-the-result-pattern) objects for control flow instead of exceptions. In common code paths like validation or business rules use Result.Failure() or Result.Success(); use Exceptions for situations like failed connection, out of memory, access array incorrectly
+- Perform all validation you can in with Input Validation, i.e. the FluentValidator. For validation on business rules i.e. if x is 3, then y can only be 5, or no duplicate calendar names, perform this in the Domain Entity. The Entity is an Aggregate, so it has all the information loaded in memory to perform these checks without reaching into the database again.
 
 ## Prerequisites